Voluntary running wheel exercise induces cognitive improvement post traumatic brain injury in mouse model through redressing aberrant excitation regulated by voltage-gated sodium channels 1.1, 1.3, and 1.6.

Traumatic brain injury (TBI) leads to disturbed brain discharge rhythm, elevated excitability, anxiety-like behaviors, and decreased learning and memory capabilities. Cognitive dysfunctions severely affect the quality of life and prognosis of TBI patients, requiring effective rehabilitation treatment. Evidence indicates that moderate exercise after brain injury decreases TBI-induced cognitive decline. However, the underlying mechanism remains unelucidated. Our results demonstrate that TBI causes cognitive impairment behavior abnormalities and overexpression of Nav1.1, Nav1.3 and Nav1.6 proteins inside the hippocampus of mice models. Three weeks of voluntary running wheel (RW) exercise treatments before or/and post-injury effectively redressed the aberrant changes caused by TBI. Additionally, a 10% exercise-conditioned medium helped recover cell viability, neuronal sodium current and expressions of Nav1.1, Nav1.3 and Nav1.6 proteins across cultured neurons after injury. Therefore, the results validate the neuroprotection induced by voluntary RW exercise treatment before or/and post-TBI. The RW exercise-induced improvement in cognitive behaviors and neuronal excitability could be associated with correcting the Nav1.1, Nav1.3, and Nav1.6 expression levels. The current study proves that voluntary exercise is an effective treatment strategy against TBI. The study also highlights novel potential targets for rehabilitating TBI, including the Navs proteins.

[Mechanism of total flavonoids of Ziziphora clinopodioides in improving atherosclerosis by regulating PI3K/Akt/mTOR pathway].

The present study observed the regulatory effect of total flavonoids of Ziziphora clinopodioides on autophagy and the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)/mammalian target of rapamycin(mTOR) signaling pathways in ApoE~(-/-) mice and explored the mechanism of total flavonoids of Z. clinopodioides against atherosclerosis(AS). ApoE~(-/-) mice were fed on a high-fat diet for eight weeks to induce an AS model. The model mice were randomly divided into a model group, a positive control group, and low-, medium-and high-dose groups of total flavonoids of Z. clinopodioides, while C57BL/6J mice fed on a common diet were assigned to the blank group. The serum and aorta samples were collected after intragastric administration for 12 weeks, and the serum levels of total cholesterol(TC), triglyceride(TG), low density lipoprotein-cholesterol(LDL-C), and high density lipoprotein-cholesterol(HDL-C) were detected by an automatic biochemical analyzer. The serum expression levels of intercellular adhesion molecule-1(ICAM-1), vascular cell adhesion molecule-1(VCAM-1), matrix metalloproteinase-2(MMP-2), and matrix metalloprotei-nase-9(MMP-9) were detected by enzyme-linked immunosorbent assay(ELISA). Oil red O staining was used to observe the aortic plaque area in mice. Hematoxylin-eosin(HE) staining was used to observe the aortic plaque and pathological changes in mice. The expression of P62 and LC3 in the aorta was detected by the immunofluorescence method. The protein expression of LC3Ⅱ/Ⅰ, Beclin-1, P62, p-PI3K, p-Akt, and p-mTOR in the aorta of mice was detected by Western blot. The results showed that compared with the blank group, the serum levels of TC, TG, LDL-C, ICAM-1, VCAM-1, MMP-2 and MMP-9 in the model group were significantly increased(P<0.01 or P<0.05), the content of HDL-C was decreased(P<0.05), intra-aortic plaque area was enlarged(P<0.01), the expression of LC3 in the aorta was significantly down-regulated, P62 expression was up-regulated(P<0.01 or P<0.05), the expressions of LC3Ⅱ/Ⅰ and Beclin-1 in the aortic lysate were significantly down-regulated, and the expressions of p-PI3K, p-Akt, p-mTOR and P62 were significantly increased(P<0.01). The medium-and high-dose groups of total flavonoids of Z. clinopodioides could reduce the serum levels of TC, TG, LDL-C, ICAM-1, VCAM-1, MMP-2, and MMP-9 in AS model mice(P<0.01 or P<0.05), and increase the content of HDL-C(P<0.01 or P<0.05). The aortic plaque area of mice after middle and high doses of total flavonoids of Z. clinopodioides was significantly reduced(P<0.01), the content of foam cells decrease, and the narrowing of the lumen decreased. The total flavonoids of Z. clinopodioides significantly increased the expression of LC3 in the aorta and the expression of LC3Ⅱ/Ⅰ and Beclin-1 in the lysate, and decreased the expression of P62 in the aorta and the expression of p-PI3K, p-Akt, p-mTOR and P62 in the lysate(P<0.01 or P<0.05). The results showed that the total flavonoids of Z. clinopodioides could improve the content of blood lipids and inflammatory factors, and reduce the generation of foam cells and plaques in aortic tissue, and the mechanism may be related to the regulation of PI3K/Akt/mTOR signaling pathway.

Reduced Expression of Voltage-Gated Sodium Channel Beta 2 Restores Neuronal Injury and Improves Cognitive Dysfunction Induced by Aß1-42.

Voltage-gated sodium channel beta 2 (Nav2.2 or Navß2, coded by SCN2B mRNA), a gene involved in maintaining normal physiological functions of the prefrontal cortex and hippocampus, might be associated with prefrontal cortex aging and memory decline. This study investigated the effects of Navß2 in amyloid-ß 1-42- (Aß1-42-) induced neural injury model and the potential underlying molecular mechanism. The results showed that Navß2 knockdown restored neuronal viability of Aß1-42-induced injury in neurons; increased the contents of brain-derived neurotrophic factor (BDNF), enzyme neprilysin (NEP) protein, and NEP enzyme activity; and effectively altered the proportions of the amyloid precursor protein (APP) metabolites including Aß42, sAPPα, and sAPPß, thus ameliorating cognitive dysfunction. This may be achieved through regulating NEP transcription and APP metabolism, accelerating Aß degradation, alleviating neuronal impairment, and regulating BDNF-related signal pathways to repair neuronal synaptic efficiency. This study provides novel evidence indicating that Navß2 plays crucial roles in the repair of neuronal injury induced by Aß1-42 both in vivo and in vitro.

Antibodies Specific to Membrane Proteins Are Effective in Complement-Mediated Killing of Mycoplasma bovis.

The metabolic inhibition (MI) test is a classic test for the identification of mycoplasmas, used for measuring the growth-inhibiting antibodies directed against acid-producing mycoplasmas, although their mechanism still remains obscure. To determine the major antigens involved in the immune killing of Mycoplasma bovis, we used a pulldown assay with anti-M. bovis antibodies as bait and identified nine major antigens. Among these antigens, we performed the MI test and determined that the growth of M. bovis could be inhibited effectively in the presence of complement by antibodies against specifically membrane protein P81 or UgpB in the presence of complement. Using a complement killing assay, we demonstrated that M. bovis can be killed directly by complement and that antibody-dependent complement-mediated killing is more effective than that by complement alone. Complement lysis and scanning electron microscopy results revealed M. bovis rupture in the presence of complement. Together, these results suggest that the metabolic inhibition of M. bovis is antibody-dependent complement-mediated killing. This study provides new insights into mycoplasma killing by the complement system and may guide future vaccine development studies for the treatment of mycoplasma infection. Furthermore, our findings also indicate that mycoplasmas may be an appropriate new model for studying the lytic activity of membrane attack complex (MAC).

A multicentre study of meticillin-resistant Staphylococcus aureus in acute bacterial skin and skin-structure infections in China: susceptibility to ceftaroline and molecular epidemiology.

Ceftaroline is a novel cephalosporin with activity against Gram-positive organisms, including meticillin-resistant Staphylococcus aureus (MRSA). The objective of this study was to investigate the susceptibility to ceftaroline of hospital-associated MRSA (HA-MRSA) isolates causing acute bacterial skin and skin-structure infections (ABSSSIs) in China and to examine their relationship by genotyping. A total of 251 HA-MRSA isolates causing ABSSSIs were collected from a multicentre study involving 56 hospitals in 38 large cities across 26 provinces in mainland China. All isolates were characterised by multilocus sequence typing (MLST), staphylococcal cassette chromosome mec (SCCmec) typing, spa typing and detection of the Panton-Valentine leukocidin locus (lukS-PV and lukF-PV). Minimum inhibitory concentrations (MICs) of 14 antimicrobial agents, including ceftaroline, were determined by broth microdilution and were interpreted using Clinical and Laboratory Standards Institute breakpoints. The ceftaroline MIC50 and MIC90 values (MICs that inhibit 50% and 90% of the isolates, respectively) were 1 µg/mL and 2 µg/mL, respectively; 33.5% (n=84) of the isolates studied were ceftaroline-non-susceptible, with MICs of 2 µg/mL, but no isolate exhibited ceftaroline resistance (MIC>2 µg/mL). All of the ceftaroline-non-susceptible isolates belonged to the predominant HA-MRSA clones: 95.2% (n=80) from MLST clonal complex 8 (CC8), with the remaining 4.8% (n=4) from CC5. The high rate of non-susceptibility to ceftaroline amongst HA-MRSA causing ABSSSIs in China is concerning.

The widely used ATB FUNGUS 3 automated readings in China and its misleading high MICs of Candida spp. to azoles: challenges for developing countries' clinical microbiology labs.

The rapid development in the clinical microbiology diagnostic assays presents more challenges for developing countries than for the developed world, especially in the area of test validation before the introduction of new tests. Here we report on the misleading high MICs of Candida spp. to azoles using the ATB FUNGUS 3 (bioMérieux, La Balme-les Grottes, France) with automated readings in China to highlight the dangers of introducing a diagnostic assay without validation. ATB FUNGUS 3 is the most commonly used commercial antifungal susceptibility testing method in China. An in-depth analysis of data showed higher levels of resistance to azoles when ATB FUNGUS 3 strips were read automatically than when read visually. Based on this finding, the performance of ATB FUNGUS 3, read both visually and automatically, was evaluated by testing 218 isolates of five clinically important Candida species, using broth microdilution (BMD) following CLSI M27-A3 as the gold-standard. The overall essential agreement (EA) between ATB visual readings and BMD was 99.1%. In contrast, the ATB automated readings showed higher discrepancies with BMD, with overall EA of 86.2%, and specifically lower EA was observed for fluconazole (80.7%), voriconazole (77.5%), and itraconazole (73.4%), which was most likely due to the trailing effect of azoles. The major errors in azole drug susceptibilities by ATB automated readings is a concern in China that can result in misleading clinical antifungal drug selection and pseudo high rates of antifungal resistance. Therefore, the ATB visual reading is generally recommended. In the meantime, we propose a practical algorithm to be followed for ATB FUNGUS 3 antifungal susceptibility for Candida spp. before the improvement in the automated reading system.